OST Sizing Guidance Changes
The Outlook 2007 SP1 update 968009 (http://support.microsoft.com/?id=968009) improves the Outlook 2007 performance, as follows:
Hopefully you have seen the news regarding the release of the Outlook 2007 SP1 February 2009 cumulative update. If you haven't, then you can read http://support.microsoft.com/?id=968009for all the detail, but basically we have made significant improvements in terms of Outlook's performance and responsiveness:
- General Responsiveness - the Outlook 2007 SP1 February 2009 cumulative update reduces I/O disk usage and UI response time.
- Startup - the Outlook 2007 SP1 February 2009 cumulative update removes long operations from initial startup (please note that there is a one-time data structure upgrade cost after the first install that takes a relatively linear amount of time based on the size of your PSTs and OST).
- Shutdown - the Outlook 2007 SP1 February 2009 cumulative update makes Outlook exit predictably despite pending activities (for more information, please see http://msdn.microsoft.com/en-us/library/dd239276.aspx).
- Folder/View Switch - the Outlook 2007 SP1 February 2009 cumulative update improves view rendering and folder switching.
Note: All of these fixes will be included in Office 2007 SP2 (and as a bit of historical trivia, all of these fixes were originally intended for SP2, but based on their quality and the rigorous testing that has been done with them, the Outlook team made the decision to backport the SP2 work into this cumulative update so that you, our customers, can take advantage of the changes sooner rather than later).
In the past, from an Exchange perspective, we made a statement with regards to the Outlook 2007 Cached Exchange Mode experience (notably in the Mailbox Server Storage DesignTechNet article) along the lines of 1 GB mailboxes with around 1 GB RAM requires at least 5400 RPM hard disks, and 2 GB mailboxes with 1-2 GB of RAM requires at least a 7200 RPM hard disk. We also recommended for high performance on mailboxes larger than 2 GB, that you reduce your mailbox size or use Online Mode. This guidance is no longer applicable with the latest product update.
Read more at source: http://msexchangeteam.com/archive/2009/03/24/450881.aspx